1. Field of the Invention
The present invention relates to apparatus for manipulating (typically focussing) laser beams and has been developed with particular attention to its use in robot systems for cutting, welding, etc.
2. Description of the Prior Art
In this context, both lens systems and mirror systems are known for focussing power laser beams.
Lens systems generally have the disadvantage that they are very vulnerable to phenomena such as scratching, etc. which make it necessary for the damaged lenses to be replaced completely.
Mirror focussing system, for example with parabolic mirrors, have the advantage in this respect that, if they have superficial scratching, they can be polished which can restore the mirror surfaces to the desired operative conditions. On the other hand, mirror focussing systems give rise to greater operative difficulties both as regards the focussing of the beam along the axis of the robot hand or wrist (with consequent repercussions on the numerical control of the robot's movements along its various axes) and because of the need to arrange the various mirrors in very strict optical alignment along the radiation path.